The heat increment of feeding and its thermoregulatory implications in the short-tailed shrew (Blarina brevicauda)

2003 ◽  
Vol 81 (8) ◽  
pp. 1445-1453 ◽  
Author(s):  
Allyson G Hindle ◽  
Ian W McIntyre ◽  
Kevin L Campbell ◽  
Robert A MacArthur
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Nutritional Status ◽  
Blarina Brevicauda ◽  
Open Flow ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Rate Of Oxygen Consumption ◽  
Excretion Rates

The nature and potential thermoregulatory benefits of the heat increment of feeding (HIF) were investigated in short-tailed shrews (Blarina brevicauda). At thermoneutrality, the postprandial rate of oxygen consumption ([Formula: see text]O2) of shrews increased by an average of 18% beyond fasting levels for ca. 2 h following the consumption of 3.5 g of earthworms. Over the same period, body temperature increased by an average of 0.6 °C. The digesta-retention time calculated from nickel alloy tracer excretion rates (168.1 ± 11.4 min (mean ± SE); n = 7) exceeded the duration of HIF (117.5 ± 10.4 min; n = 6) by 43%. This finding suggests that the mechanical costs of feeding may be a relatively mi nor component of HIF in this species. Regression of resting [Formula: see text]O2 on ambient temperature (Ta) below thermo neutrality yielded similar slopes (P = 0.71) and intercepts (P = 0.33) for fed and fasted animals, suggesting that HIF substitutes, at least partially, for facultative thermogenesis at low Ta. We found no evidence that HIF enhanced microclimate warming of an insulated, open-flow metabolic chamber occupied by recently fed shrews. Occupancy of this chamber by shrews increased microclimate Ta from 5 to 9.0–9.5 °C regardless of their nutritional status.

scholarly journals Heat increment of feeding in Brunnich's guillemot

1997 ◽  
Vol 200 (12) ◽  
pp. 1757-1763 ◽  
Author(s):  
P Hawkins ◽  
P Butler ◽  
A Woakes ◽  
G Gabrielsen
Keyword(s):  
Oxygen Consumption ◽  
Energetic Cost ◽  
Uria Lomvia ◽  
Deep Body Temperature ◽  
Common Murre ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Rate Of Oxygen Consumption ◽  
Free Ranging ◽  
Persistent Elevation

The rate of oxygen consumption (O2), respiratory quotient (RQ) and deep body temperature (TB) were recorded during a single, voluntary ingestion of Arctic cod Boreogadus saida (mean mass 18.9+/-1.1 g, s.e.m., N=13) by five postabsorptive Brunnich's guillemots (thick-billed murre, Uria lomvia). The birds were resting in air within their thermoneutral zone, and the fish were refrigerated to 0-2 degreesC. The rate of oxygen consumption increased by a factor of 1.4 during the first few minutes after ingestion, but there was no significant change in TB. Mean rate of oxygen consumption returned to preingestive levels 85 min after the birds ate the fish. The telemetered temperature of one fish reached TB within 20 min. This suggests that the persistent elevation in O2 over the next hour corresponded to the obligatory component of the heat increment of feeding (HIF) and was not related to heating the fish. Abdominal temperature increases after diving bouts in free-ranging common guillemots (common murre, Uria aalge) are possibly achieved through the HIF, since meals are processed at sea. Of the increase in O2 measured in the laboratory, it is calculated that 30 % is required to heat the fish, while 70 % is due to the HIF. In free-ranging birds, the excess heat provided by the HIF could contribute 6 % of the daily energy expenditure. This suggests that the HIF augments heat production in Uria spp. and thus reduces the energetic cost of thermoregulation.

Compensatory effect of the heat increment of feeding on thermoregulation costs of white-tailed deer fawns in winter

1999 ◽  
Vol 77 (9) ◽  
pp. 1474-1485 ◽  
Author(s):  
Paul G Jensen ◽  
Peter J Pekins ◽  
James B Holter
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Resting Metabolic Rate ◽  
Energetic Cost ◽  
Critical Temperatures ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Minor Portion ◽  
A Minor

For northern white-tailed deer (Odocoileus virginianus) fawns, the energetic cost of thermoregulation (HcE) during severe winters can result in substantial catabolism of body-tissue reserves. The heat increment of feeding (HiE) has the potential to offset thermoregulatory energy expenditure that would otherwise require the catabolism of these reserves. During winters 1996 and 1997, we conducted 18 fasting and 18 on-feed heat-production trials using indirect respiration calorimetry in a metabolic chamber. Nonlinear regression analysis was used to estimate the lower critical temperatures (Tlc) and determine the fasting metabolic rate (FMR) and resting metabolic rate (RMR). Resulting models were used to calculate HiE, HcE, and percent substitution of HiE for HcE. For fawns fed a natural browse diet, estimated FMR and RMR were 352 and 490 kJ·kg body mass (BM)-0.75·d-1, respectively; this 40% increase in thermoneutral heat production reduced Tlc from -0.8 to -11.2°C between the fasted and fed states, respectively, and reduced HcE by 59% for fed fawns. For fawns fed a concentrate diet, estimated FMR and RMR were 377 and 573 kJ·kg BM-0.75·d-1, respectively. Level of browse intake had a significant effect on RMR andTlc. RMR was 12% higher for fawns on a high versus a low level of intake, and estimated Tlc was -15.6 and -5.8°C, respectively. Our data indicate that the energetic cost of thermoregulation is probably a minor portion of the energy budget of a healthy fawn consuming natural forage.

CNS regulation of body temperature in euthermic and hibernating marmots (Marmota flaviventris)

1977 ◽  
Vol 232 (5) ◽  
pp. R203-R208 ◽  
Author(s):  
G. L. Florant ◽  
H. C. Heller
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Marmota Flaviventris ◽  
Hypothalamic Temperature ◽  
Proportionality Constant ◽  
Metabolic Heat ◽  
Slow Decline ◽  
Rate Of Oxygen Consumption ◽  
Hypothalamic Thermosensitivity ◽  
Deep Hibernation

Hypothalamic thermosensitivity of marmots was characterized during euthermia and hibernation. Hypothalamic temperature (Thy) was manipulated with chronically implanted, water-perfused thermodes while the animal's rate of oxygen consumption was continuously measured. The threshold Thy for eliciting an increase in metabolic heat production (MHP) and the proportionality constant (alphaMHP) relating rate of MHP to Thy were determined. In four euthermic marmots alphaMHP averaged -1.1 W-kg-1-degrees C-1. During the entrance into hibernation, as body temperature (Tb) declined from 36 to 8 degrees C, the threshold Thy for the MHP response progressively declined and was demonstrable at all times. The Thy of marmots in deep hibernation at an ambient temperature (Ta) of 5 degrees C plateaued near 7.5 degrees C, but threshold Thy for MHP showed a continuous slow decline of 0.2-0.4 degrees C a day, until one day prior to arousal. Proportional regulation of Tb was demonstrable at all times during deep hibernation. The average proportionality constant for the MHP response to hypothalamic cooling during deep hibernation in three marmots was -0.08 W-kg-1-degrees C-1. These results demonstrate that the hypothalamic regulator of Tb is active throughout hibernation and that there are progressive changes in its thermosensitivity.

Hibernation in the Eastern Pygmy Possum, Cercartetus-Nanus (Marsupialia, Burramyidae)

1993 ◽  
Vol 41 (1) ◽  
pp. 67 ◽  
Author(s):  
F Geiser
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Air Temperature ◽  
The Body ◽  
Daily Torpor ◽  
Rate Of Oxygen Consumption ◽  
The Mean ◽  
Cercartetus Nanus ◽  
Torpor Bouts

The pattern of torpor was examined in the eastern pygmy possum, Cercartetus nanus (21 g). Animals displayed torpor regularly in the laboratory, and the occurrence of torpor increased with decreasing air temperature (T(a)). At high T(a) (18-degrees-C) animals usually exhibited daily torpor, but torpor bouts of up to 2 days were observed occasionally. The duration of torpor bouts lengthened with a lowering of T(a) and the mean bout duration at T(a) = 5-degrees-C was 17.0 +/- 2.5 days. The minimum metabolic rate (measured as rate of oxygen consumption) of torpid individuals was 0.018 +/- 0.003 mL O2 g-1 h-1, which is less than 2% of the basal metabolic rate. The body temperature (T(b)) Of torpid animals fell to a minimum of 1.3 +/- 0.4-degrees-C. These results clearly demonstrate that Cercartetus nanus is a deep hibernator.

Factorial scopes of cardio-metabolic variables remain constant with changes in body temperature in the varanid lizard, Varanus rosenbergi

2005 ◽  
Vol 288 (4) ◽  
pp. R992-R997 ◽  
Author(s):  
T. D. Clark ◽  
T. Wang ◽  
P. J. Butler ◽  
P. B. Frappell
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Oxygen Affinity ◽  
Aerobic Performance ◽  
Specific Rate ◽  
Aerobic Scope ◽  
Thermal Dependence ◽  
Hemoglobin Oxygen Affinity ◽  
Rate Of Oxygen Consumption ◽  
Metabolic Performance

The majority of information concerning the cardio-metabolic performance of varanids during exercise is limited to a few species at their preferred body temperature (Tb) even though, being ectotherms, varanids naturally experience rather large changes in Tb. Although it is well established that absolute aerobic scope declines with decreasing Tb, it is not known whether changes in cardiac output (V̇b) and/or tissue oxygen extraction, (CaO2 − Cv�[Formula: see text]), are in proportion to the rate of oxygen consumption (V̇o2). To test this, we studied six Rosenberg's goannas ( Varanus rosenbergi) while at rest and while maximally exercising on a treadmill both at 25 and 36°C. During maximum exercise both at 25 and 36°C, mass-specific rate of oxygen consumption (V̇o2kg) increased with an absolute scope of 8.5 ml min−1 kg−1 and 15.7 ml min−1 kg−1, respectively. Interestingly, the factorial aerobic scope was temperature-independent and remained at 7.0 which, at each Tb, was primarily the result of an increase in V̇bkg, governed by approximate twofold increases both in heart rate ( fH) and cardiac stroke volume (VSkg). Both at 25°C and 36°C, the increase in V̇bkg alone was not sufficient to provide all of the additional oxygen required to attain maximal V̇o2kg, as indicated by a decrease in the blood convection requirement V̇bkg/V̇o2kg; hence, there was a compensatory twofold increase in (CaO2 − [Formula: see text]). Although associated with an increase in hemoglobin-oxygen affinity, a decrease in Tb did not impair unloading of oxygen at the tissues and act to reduce (CaO2 − Cv�[Formula: see text]); both CaO2 and Cv�[Formula: see text] were maintained across Tb. The change in V̇o2kg with Tb, therefore, is solely reliant on the thermal dependence of V̇bkg. Maintaining a high factorial aerobic scope across a range of Tb confers an advantage in that cooler animals can achieve higher absolute aerobic scopes and presumably improved aerobic performance than would otherwise be achievable.

Metabolic expenditure of waleye (Stizostedion vitreum vitreum) as determined by rate of oxgen consumption

1981 ◽  
Vol 59 (6) ◽  
pp. 882-889 ◽  
Author(s):  
Martin J. Tarby
Keyword(s):  
Oxygen Consumption ◽  
Unit Weight ◽  
Stizostedion Vitreum ◽  
Regression Equations ◽  
Feeding Experiments ◽  
Standard Metabolism ◽  
Heat Increment ◽  
Rate Of Oxygen Consumption ◽  
The Difference ◽  
Metabolic Expenditure

Energy expended by walleye (Stizostedion vitreum vitreum) for metabolism was assessed by measuring oxygen consumption of different size fish in respirometers under various conditions of temperature, activity, and ration. Standard metabolism was estimated as rate of oxygen consumption of unfed resting fish, and relationships to weight and temperature were expressed by simple and multiple regression equations. Although slopes for simple regressions did not differ significantly from slopes for analogous equations determined previously for walleye in maintenance feeding trials, the intercept or level of metabolism for a fish of unit weight at 20 °C computed from feeding experiments was over three times greater than that computed by respirometry. Heat increment, which was quantified from the difference in oxygen consumption of resting walleye fed and deprived of food at 20 °C, ranged from about 9 to 11% of the energy ingested and appeared independent of ration and fish size. Metabolism for swimming determined as the difference between rate of oxygen consumption of unfed fish resting and swimming one body length per second was calculated to be approximately equal to the energy expended by walleye for standard metabolism.

Metabolic and behavioral responses of muskrats (Ondatra zibethicus) to elevated CO2 in a simulated winter microhabitat

1986 ◽  
Vol 64 (3) ◽  
pp. 738-743
Author(s):  
Robert A. MacArthur
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Behavioral Responses ◽  
Metabolic Responses ◽  
Foraging Activity ◽  
Ondatra Zibethicus ◽  
Daily Rate ◽  
Rate Of Oxygen Consumption ◽  
Breathing Room ◽  
Avoidance Reactions

Metabolic and behavioral responses to inspired CO2 were investigated in muskrats housed in a microhabitat designed to simulate winter field conditions. Mean daily rate of oxygen consumption [Formula: see text] declined from 1.46 mL O2∙g∙h−1 in animals breathing room air to 1.11–1.25 mL O2∙g∙h−1 in animals inhaling 4–10% CO2 in the simulated lodge. Daily patterns of [Formula: see text], abdominal body temperature (Tb), and foraging activity were minimally affected by chronic CO2 exposure, though muskrats breathing 9–10% CO2 made shorter voluntary dives. The ability of muskrats to rewarm following foraging activity was slightly depressed by hypercapnia. Abrupt exposure of resting animals to ambient CO2 levels of 10–16% often elicited avoidance reactions in the absence of any apparent change in [Formula: see text] or Tb. This study provides the first demonstration of behavioral and metabolic responses by muskrats to CO2 levels encountered in the winter microhabitat of this species.

Energetics of surface swimming in Brandt's cormorants (Phalacrocorax penicillatus brandt)

2000 ◽  
Vol 203 (24) ◽  
pp. 3727-3731 ◽  
Author(s):  
A. Ancel ◽  
L.N. Starke ◽  
P.J. Ponganis ◽  
R. Van Dam ◽  
G.L. Kooyman
Keyword(s):  
Oxygen Consumption ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Energy Requirements ◽  
Swimming Velocity ◽  
Specific Rate ◽  
Cost Of Transport ◽  
Metabolic Chamber ◽  
Rate Of Oxygen Consumption ◽  
The Cost

The energy requirements of Brandt's cormorants (Phalacrocorax penicillatus) during surface swimming were measured in birds swimming under a metabolic chamber in a water flume. From the oxygen consumption recordings, we extrapolated the metabolic rate and cost of transport at water speeds ranging from 0 to 1.3 m s(−)(1). In still water, the birds' mean mass-specific rate of oxygen consumption (V(O2)) while floating at the surface was 20.2 ml O(2)min(−)(1)kg(−)(1), 2.1 times the predicted resting metabolic rate. During steady-state voluntary swimming against a flow, their V(O2) increased with water speed, reaching 74 ml O(2)min(−)(1)kg(−)(1) at 1.3 m s(−)(1), which corresponded to an increase in metabolic rate from 11 to 25 W kg(−)(1). The cost of transport decreased with swimming velocity, approaching a minimum of 19 J kg(−)(1)m(−)(1) for a swimming speed of 1.3 m s(−)(1). Surface swimming in the cormorant costs approximately 18 % less than sub-surface swimming. This confirms similar findings in tufted ducks (Aythya fuligula) and supports the hypothesis that increased energy requirements are necessary in these birds during diving to overcome buoyancy and heat loss during submergence.

METABOLISM, FOOD CAPACITY, AND FEEDING BEHAVIOR IN FOUR SPECIES OF SHREWS

1964 ◽  
Vol 42 (2) ◽  
pp. 259-279 ◽  
Author(s):  
Charles H. Buckner
Keyword(s):  
Oxygen Consumption ◽  
Feeding Habits ◽  
Carbon Dioxide Production ◽  
Nitrogen Excretion ◽  
Effective Control ◽  
Blarina Brevicauda ◽  
Larch Sawfly ◽  
Sorex Cinereus ◽  
Rate Of Oxygen Consumption ◽  
Minimum Numbers

The metabolic rates of Sorex cinereus, Sorex arcticus, Microsorex hoyi, and Blarina brevicauda were calculated from oxygen consumption, carbon dioxide production, and urinary nitrogen excretion and found to be 6.1, 6.9, 67, and 9.7 Calories per animal per day respectively. The resting rate of oxygen consumption was lower for S. cinereus than values reported by previous authors and was probably close to the basal level. Respiratory quotients were higher than expected for carnivorous animals, averaging 0.83 for all species. Protein catabolism accounted for about half the daily caloric output. Metabolic rate increased with increasing population densities.The minimum numbers of larch sawfly eonymphs required to support the daily metabolic requirements, including fecal wastage, for S. cinereus, S. arcticus, M. hoyi, and B. brevicauda were 87, 123, 98, and 150 respectively. Because of digestive inefficiency and wasteful feeding habits the approximate numbers of eonymphs destroyed daily could be as high as 663, 570, 711, and 150, and if hoarding is considered, 833, 790, 891, and 410 respectively could be taken. Excepting B. brevicauda, the larch sawfly is a preferred food of the group and, when available in abundance, comprises over 70% of the diet. It was estimated that shrews have the capacity to consume numbers of cocoons in excess of naturally occurring populations, but the likelihood of complete destruction of populations is remote. Of the species studied, S. cinereus appeared to be the most likely to provide effective control of larch sawfly populations.

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